XIOS

a library dedicated to I/O management in climate codes

XIOS, standing for XML-IO-Server, is a library dedicated to I/O management in climate codes. XIOS manages output of diagnostics and other data produced by climate component codes into files and offers temporal (average, minimum, maximum, etc.) and spatial post-processing operations on this data. XIOS aims at simplifying the I/O management in the codes by minimizing the number of subroutine to be called in the code and reducing the number of arguments of these subroutines. The output definition is outsourced in an XML file and this allows easily changing the output configuration without recompiling. XIOS is fully parallel and targets climate models running on large number of cores. Its efficiency is based on the server concept into which one or more additional processes are exclusively dedicated to the asynchronous writing of the data into files. XIOS is extensively used in the NEMO ocean framework and starts to be used into more and more climate components in Europe.